Resinous composition comprising polyvinyl chloride plasticized with adducts of tetrahydrophthalate and end omethylenehydrophthalate esters with fumarate esters



United States Patent 'RESINOUS CONIPUSITION COMPRISING POLY- VINYLCHLORIDE PLASTICIZED AD- DUCTS OF TE'I-RAHYDROPHTHALATE AND END OMETHYL'ENEHYDROPHTHALATE ES- TERS WITH FUMARATE Joachim Dazzi, Dayton, Ohio,assig'nor to Monsanto Chemical Company, St. Louis, 'M0., "a corporationof Delaware No Drawing. Original application Mar. 4, 1955, Ser.No.492,300, now Patent No.j2,850,523, dated Sept. 2, 1958. Divided andthis-application'Mar. 24, 1958, :Ser. No. 723,145

Claims. (0.260 313) This invention relates to high molecular weightadducts and more particularly provides partially hydrogenatedcycloalkenes having a plurality of carboxylate radicals and a process ofproducing the same.

An object of the invention is the provision'ofnew-and usefulpolycarboxylates. Another object of the invention is the preparation ofviscous polycarboxylates from Diels-Alder diene synthesis additionproducts. Still another object of the invention is to'providefro'm thecoati'ngs, synthetic resins and plastics, plasticizer, rubber "andtextile industries a new class of stable, viscous materials having-aplurality of carboxylate radicals.

These and other objects of "the invention hereinafter disclosed areprovided by the following invention "wherein there ar'e' prepared-visco'us adducts'of (1") and alkyl fumarate having from 1 'to 8 carbonatoms 'in'the alkyl radical and (2) the'completely esterifieddienesynthesis addition product of maleic 'anhydride and 1a conjugateddienic hydroc'arb'onof fr'om 4 to 6 "carbon atoms, the alcohol portionof said ester b'eing'derivedfrom a'fatty alcohol of from 1 to 8 carbonatoms.

Alkyl fumarates suitable for the present purpose are the simple diestersof fumaric acid, e.g., methyl, ethyl, isopropyl, n-propyl, n-butyl,tert-butyl, isoamyLn-hexyl, n-heptyl, 2-ethylhexyl and n-octyl fumarate,or the-mixed diesters, e.g., ethyl methyl fumarate, isopropyl n-octylfumarate, n-amyl tert-butyl fumarate, etc.

-Esterified Diels-Alder adducts of'maleic anhydride and dienichydrocarbons with which the alkyl fumarates are reacted according to theinvention -to give the present viscous polycarboxylates are alkyltetrahydrophthalates or endomethylene-tetrahydrophthalates obtained inknown manner by esterification of the Diels-Alder 1,4- addition productsof maleic anhydride and dienes such as 1,3-butadiene, isoprene,piperylene, 2-methyl-l,3- pentadiene, 2,3-dimethyl-1,B-butadiene,cyclopentadiene, methyl-cyclopentadiene, etc. Diels-Alder additionproducts obtained from maleic anhydride and an open-chain conjugateddienic hydrocarbon of from 4 to 6 carbon atoms are-l,2,3,6-tetrahydrophthalic anhydrides of the formula where R denoteshydrogen, methyl or ethyl and in which the sum of the carbon atoms inthe total R substitue'nts is less than 3. Products obtained from :maleicanhydride and a cyclic conjugated dienic hydrocarbon of cyclopentadieneand mal-eic anliydride being"3,6-endomethylene-l,2,3,6-tetrahydrophthalic anhydride ii l on-o=o Hrr- :0

For-production of the present viscous adducts, it is preferable to firstesterify the Diels-Alder maleic anhydridediene addition product bycondensing it with a fatty alcohol of from 1 to 8 carbon atoms and thenreact the esterified addition product with'the alkyl fumarate, wherebythere occurs addition of the esterified product with the fumarate. WhileI do not know the mechanism by which addition of the fumarate to theDiels-Alder product occurs, it probably takes place at the carbon atomor atoms which are octo the carbon atoms attached to the olefinic doublebond of said -Diels-Alder product. Depending upon the reactionconditions and the nature of thefumarate and Diels-Alder product, from 1to 2 moles of fumarate 'add to said product. Hence the present compoundshave from 4 to 6 carboxylate groups two groups beingpresent originallyin the maleic anhydridediene addition product, 2 carboxylate radicalsbeing introduced upon addition of one mole of an alkyl fumarate to theDiels-Alder product, and-two additional carboxylate radicals beingintroduced upon addition of a-second mole of an alkyl fumarate.Generally the product is 'a mixture of adducts in which from 1 to 2moles of the fumarate have added to one mole of the Diels-Alder product.

Although it is preferred to esterify the maleic anhydride-dieneDiels-Alder addition product prior to reaction with the alkyl fumarate,if desired the Diels-Alder product, i.e., thetetrahydrophthalic'anhydride compound, may be reacted first with thealkyl fumarate, and then with a fatty alcohol to effect esterificationof the anhydride group of the alkyl fumarate-tetrahydrophathalicanhydride adduct.

Reaction of the esterified or unesterified Diels-A1cler addition productwith the alkyl fumarate to form the present viscous adducts takes placereadily by heating a mixture of the fumarate and the Diels-Alder productin the presence or absence of an inert diluent or solvent at ordinary orsuperatmosphericpressures. When operating at atmospheric pressure,temperatures of from, say, C. to 300 Q, and preferably of from C. to 225C., are used. The number of carboalkoxy groups introduced into theDiels-Alder addition product depends upon the nature of said product,upon the nature of the individual fumarate used, and upon the reactionconditions employed. Generally, operation within the higher temperatureranges, i.e., at temperatures of above, say 180 C. and below thedecomposition point of any of the reactants, leads to introduction ofmore carboalkoxy groups than does operation at the lower temperatures.The degree of introduction of 'carbonkexy 'groiips arse depends upon theindividual furnar ateemployed. -Usually alkyl iumar'ates having 4 or '5carbon atoms in-tli'e alkyl radical are more reactive then either thelower "or the higher alkyl fumarates. In view of the effect of reactionconditions and "nature of'the fumarat'es upon the extent ofintroductionof carboalkoxy group's, it"=is' r'e'commended that for eachinitial run there be experimentally determined the operating "conditionswhich should be observed for obtaining the desired degree ofintroduction of such groups.

The quantity of fumar-ate introduced into the Diels- Alder product willalso depend upon its availability in the reaction mixture. Obviously,for the formation of adducts in which at least one mole of the fumaratehas added to one mole of the Diels-Alder product, the equivalent amountof fumarate must be present in the reaction mixture.

Since the presently useful fumarates are miscible with the Diels-Alderproducts under the reaction conditions used, no extraneous solvent ordiluent need be employed. However, in some instances, it may beadvantageous to work with a solution of the Diels-Alder product in aninert, extraneous diluent or solvent, e.g., a liquid hydro carbon or aliquid derivative thereof, such as a high-boiling aliphatic hydrocarbon,e.g.,' kerosene. When operating at atmospheric pressure such diluent isgenerally removed before reaction of the Diels-Alder product with thefumarate occurs, due to the high temperatures used. For successfulreaction, the diluent may or may not be present.

The present Dials-Alder product-alkyl fumarate adducts are stable,high-boiling viscous liquids which are advantageously employed for avariety of industrial pur poses, for example, as textile-treating agentsand aslubricant additives. They are particularly valuable asplasticizers for vinyl chloride polymers. 'The present adducts arecompletely compatible with such polymers and show no exudation ofplasticizer even at plasticizer contents of up to 50 percent. Althoughthe quantity of plasticizer will depend upon the particular polymer tobe plasticized and upon its molecular weight, it is generally found thatcompositions having from 5 percent to 50 percent by weight of thepresent plasticizer will, in most cases, be satisfactory for generalutility. The good flexibility of the plasticized compositions increaseswith increasing plasticizer concentration.

In evaluating plasticizer efliciency, use is made of the followingempirical testing procedures:

C0mpatability.Visual inspection of the plasticized composition isemployed, incompatability of the plasticizer with the polymer beingdemonstrated by cloudiness and exudation of the plasticizer.

Low temperature flexibility.--Low temperature flexibility is one of themost important properties of elastomeric vinyl compositions. While manyplasticizers will produce flexible compositions at room temperature theflexibility of these compositions at low temperatures may varyconsiderably, i.e., plasticized polyvinyl chloride compositions that areflexible at room temperature often become very brittle and useless atlow temperatures. Low

temperature flexibility tests herein employed are according to theClash-Berg method. This method determines the torsional flexibility of aplastic at various temperatures. The temperature at which the vinylcomposition exhibits an arbitrarily established minimum flexibility isdefined as the low temperature flexibility of the composition. Thisvalue may also be defined as the lower temperature limit of theplasticized compositions usefulness as an elastomer.

V0latility.lust as a decrease in temperature often results in decreasedflexibility of a plasticized polymer composition so does a decrease inplasticizer concentration 4 Example 1 To a flask equipped withmechanical stirrer, thermometer and a Dean and Stark trap carrying areflux condenser, there was charged a mixture of 112.8 g. (0.4 mole) ofn-butyl 1,2,3,6-tetrahydrophthalate (obtained by esterifying theDiels-Alder butadiene-maleic anhydride adduct with n-butanol) and 181 g.(0.8 mole) of n-butyl fumarate. The mixture, r15 1.4511, was heated in anitrogen atmosphere for 4 hours at a temperature of from 270 C. to 276C. (refluxing). 'Distillation of the resulting reaction mixture toremove material boiling below 215 C./ 1 mm., gave as residue 169.0 g. ofthe viscous n-butyl fumarate n butyl l,2,3,6 tetrahydrophthalate adduct,n 1.4861.

Example 2 A mixture consisting of 117.6 g. (0.4 mole) of n-butyl3,6-endomethylene-1,2,3,6-tetrahydrophthalate (obtained by esterifyingthe Diels-Alder cyclopentadiene-maleic anhydride adduct with n-butanol)and 181 g. (0.8 mole) of n-butyl fumarate was charged to a flaskequipped with a mechanical stirrer, thermometer and a Dean and Starktrap carrying a reflux condenser. The mixture, having 11 1.4535, washeated in a nitrogen atmosphere at 240 C. to 25 8 C. (refluxing) for 5.5hours. Distillation of the resulting mixture to remove material boilingbelow 206 C./1 mm. gave as residue 105 g. of the viscous n butylfumarate-n-butyl 3,6-endomethylene-1,2,3,6-tetrahydrophthalate adduct, n1.4779.

Example 4 Sixty parts by weight of polyvinyl chloride and 40 parts byweight of the adduct of Example 1 were mixed on a rolling mill to ahomogeneous blend. During the milling there was observed substantiallyno fuming or discolorawhen caused by volatilization of the plasticizer.Hence,

tiou. A molded sheet of the mixture was clear and transparent andsubstantially colorless. Testing of the molded sheet for low temperatureflexibility, according to the testing procedure described above, gave avalue of minus 112 C. Testing of the volatility characteristics of theplasticized composition gave a value of 1.3 percent, which shows verygood retention of plasticizer and indicates good temperaturecharacteristics of the composition. When subjected to heat at atemperature of 325 F. for a period of 30 minutes the clarity and colorof the molded product was substantially unchanged. Testing of the waterresistance of the plasticized material employing the test proceduredescribed above showed a solids-loss of only 0.05 percent and a 1.02percent water absorption value.

-When the adduct of Example 2 was tested as a plasticizer for polyvinylchloride employing the proportions and procedure used above for theadduct of Example 1, there was obtained a clear, compatible plasticizedmaterial having a volatility value of 1.2 percent, a solids-loss valueof 0.02 percent and a water-absorption value of 0.75 percent. Similartesting of the adduct of Example 3 in the 60:40 polyvinylchloridezadduct proportions gave a clear, homogeneous test specimenhaving a volatility value of 0.6 percent, a solids-loss value of 0.03percent, and a water-absorption value of 0.53 percent. The keroseneresistance of a molded test specimen of polyvinyl chloride plasticizedwith 40 percent by weight of the adduct of Example 3 was determined asfollows:

A 2" diameter 40 mil. disc was suspended in a 50 C. oven for a 3-hourconditioning period to eliminate water, then cooled and weighed. Theconditioned sample was then immersed in 400 ml. of kerosene for a periodof 24 hours, at 27 C. The sample was then removed from kerosene, blotteddry and suspended in a force-draft 80 C. oven for 4 hours. The samplewas then cooled and weighed. The percent loss in weight was reported asthe kerosene extraction value. There was thus obtained a keroseneextraction value of 0.1 percent.

While the above example shows only compositions in which the ratio ofplasticizer to polymer content is 40:60, this ratio being employed inorder to get comparable efliciences, the content of adduct to polyvinvylchloride may be widely varied, depending upon the properties desired inthe final product. For many purposes a plasticizer content of, say, fromonly percent to 20 percent is preferred. The present adducts arecompatible with polyvinyl chloride over wide ranges of concentrations,up to 50 percent of esters based on the total weight of the plasticizedcomposition yielding desirable products.

Although the invention has been described particularly with reference tothe use of the present adducts as plasticizers for polyvinyl chloride,they are advantageously employed also as plasticizers for copolymers ofvinyl chloride, for example, the copolymers of vinyl chloride with vinylacetate, vinylidene chloride, etc. Preferably, such copolymers have ahigh vinyl chloride content, i.e., a vinyl chloride content of at least70 percent by Weight of vinyl chloride and up to 30 percent by weight ofthe copolymerizable monomer.

The plasticized polyvinyl halide compositions of the present inventionhave good thermal stability; however, for many purposes, it may beadvantageous to use known stabilizers in the plasticized compositions.Inasumuch as the present adducts are substantially unreactive with thecommercially available heat and light stabilizers which are commonlyemployed with polyvinyl chloride of copolymers thereof, the presence ofsuch materials in the plasticized materials does not impair the valuableproperties of the present esters. The present adducts are of generalutility in softening vinyl chloride polymers. They may be used as theonly plasticizing component in a compounded vinyl chloride polymer orthey may be used in conjunction with other plasticizers.

This application is a division of my copending application, Serial No.492,300, filed March 4, 1955, and now U.S. Patent No. 2,850,523, issuedSeptember 2, 1958.

What I claim is:

l. A resinous composition comprising polyvinyl chloride plasticized withthe adduct of from 1 to 2 moles of an alkyl fumarate having from 1 to 8carbon atoms in the alkyl radical and 1 mole of an alkyl1,2,3,6-tetrahydrophthalate having from 1 to 8 carbon atoms in the alkylradical, said adduct having been prepared by heating said fumarate withsaid tetrahydrophthalate at a temperature of 150 C. to 300 C., and beingfrom 5 to by weight of the composition.

2. A resinous composition comprising polyvinyl chloride plasticized withthe adduct of from 1 to 2 moles of an alkyl fumarate having from 1 to 8carbon atoms in the alkyl radical and 1 mole of an alkyl3,6-endomethylenel,2,3,6-tetrahydrophthalate having from 1 to 8 carbonatoms in the alkyl radical, said adduct having been prepared by heatingsaid fumarate with said tetrahydrophthalate at a temperature of C. to300 C., and being from 5 to 50% by weight of the composition.

3. A resinous composition comprising a vinyl chloride polymerplasticized with the adduct of from 1 to 2 moles of butyl fumarate and 1mole of butyl 1,2,15,6- tetrahydrophthalate, said adduct having beenprepared by heating said fumarate with said tetrahydrophthalate at atemperature of 150 C. to 300 C., and being from 5 to 5 0% by weight ofthe composition.

4. A resinous composition comprising polyvinyl chloride plasticized withthe adduct of from 1 to 2 moles of ethyl fumarate and 1 mole of butyl1,2,3,6-tetrahyd-rophthalate, said adduct having been prepared byheating said fumarate with said tetrahydrophthalate at a temperature of150 C. to 300 C., and being from 5 to 50% by weight of the composition.

5. A resinous composition comprising polyvinyl chloride plasticizedwithan adduct of from 1 to 2 moles of an alkyl fumarate having from 1 to8 carbon atoms in the alkyl radical and one mole of a partiallyhydrogenated phthalate compound selected from the class consisting of analkyl 1,2,3,6-tetrahydrophthalate having from 1 to 8 carbon atoms in thealkyl radical and an alkyl 3,6 endomethylene l,2,3,6-tetrahydrophthalatehaving from 1 to 8 carbon atoms in the alkyl radical, said adduct havingbeen prepared by heating said fumarate with said tetrahydrophthalate ata temperature of 150 C. to 300 C. and being from 5 to 50% by weight ofthe composition.

No references cited.

5. A RESINOUS COMPOSITION COMPRISING POLYVINYL CHLORIDE PLASTICIZED WITHAN ADDUCT OF FROM 1 TO 2 MOLES OF AN ALKYL FUMARATE HAVING FROM 1 TO 8CARBON ATOMS IN THE ALKYL RADICAL AND ONE MOLE OF A PARTIALLYHYDROGENATED PHTHALATE COMPOUUND SELECTED FROM THE CLASS CONSISTING OFAN ALKYL 1,2,3,6-TETRAHYDROPHTHALATE HAVING FROM 1 TO 8 CARBON ATOMS INTHE ALKYL RADICAL AND AN ALKYL 3,6-ENDOMETHYLENE -1,2,3,6-TETRAHYDROPHTHALATE HAVING FROM 1 TO 8 CARBON ATOMS IN THE ALKYLRADICAL, SAID ADDUCT HAVING BEEN PREPARED BY HEATING SAID FUMARATE WITHSAID TETRAHYDROPHTHALATE AT A TEMPERATURE OF 150*C. TO 300*C. AND BEINGFROM 5 TO 50* BY WEIGHT OF THE COMPOSITION.